SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db5b6224324bbfd7dc5458eb30ac439704307913d6c48ee40cff369399cdc770' 
  AND token = 'LIrH2Dsw7xdUoXTqsMlA2pXcrJNKr0o/0Ef10BNBs/4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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