SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83de677cff419e9da3addc9613835dc2728edd54325ff041c59c7d1402b75bba' 
  AND token = 'nbfhP/y6HCy3glfzH/wLBCJhPcfUqsauhff/8YbwG/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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