SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dd7a7013c0badc59c56468c9792e20179912684671d79d5b86b0f508b6259a7' 
  AND token = 'bx7eBI6Px2ZMikhwQb0VNQx3csyiHZUszvkMHuqJ+Tc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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