SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a76080beb55cd5dba384106d27e496fd0b148322bc62a3f6636997d8b94f1ef7' 
  AND token = 'g6+nvVA6Fn+JcRGnZrOpy0R7WlLm3VzvAjDpDEK36uE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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