SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b22e00d23f4bb8cc28a7b40ea718d598fab60df5ea23dc7510e8a19d9ac931d' 
  AND token = '1PKM663ztPhV32+gpXtJKKiweHVP6bKm7qfdRvnsUNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}