SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae7c18e6162b0397fe792606b0b993f362195105e5ec3ec05d0648d663dda822' 
  AND token = 'ut7nxyRZm1/VlmyZcyLPBZbb+QajbwZSPNv4YOZ9UBQ=' 
  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"
    }
  }
}