SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de8099522f3cf288a3808e79ed2015c55f4f66359f61ba3e5adacfbb60750dfe' 
  AND token = 'w2twFwZ0aj3tfMLReXfyqj8UuBFLFH3lNByr0BMl9Ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}