SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e029390d37cdd1e4f9d7cb7f2ed8a415d282da2ccfff4aa832665fc483d8e77' 
  AND token = 'tfMfmbLGelFHhSHPlQa/sAsiP3ozlKHJNAq6Ugooetg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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