SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b27b6583b13cbecc6c5d81ed8570d591d4c6198d0abcf993d4900644dfd6f6db' 
  AND token = 'IFHlMmFsYJK8KkxrCG3HDkTENQfhfmf25qfcvHEcxME=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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