SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2af88005f568ef899965c3db7cf3e00502f755e506d97af5f26c6e0e820997ff' 
  AND token = '7Yc72rBmqNXAjb/dsJOsP8BDiVy3VyFlotQmGg5r0cA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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