SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c14e60a3a9fb655d5ad3455d6ecd3754f701502cd3be836146307b883aa4fd75' 
  AND token = 'B/BXqvLzBpO2auO/aEosviIcPUcwOk2L4s9cSeJPfos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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