SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '680779cf46234e669e6617583ade7ffd42ef398d023462eaa013cbb3cf072538' 
  AND token = 'mwlw6BDzWBdo6HX0/S73PBSY/SCINx7vP6KZFZolIao=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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