SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b08f4dd6bcc915f5b5fa2d4f47bf344697ef24e0c5030623863b2612720ee7a7' 
  AND token = 'D701gbeVNvd21gD0b8L10SACKwo+o9XnuPKLECUZygE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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