SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45a2f4cb383828224cb0521c240b1f8b4c62d9423a584945be3e2757f3913b0b' 
  AND token = 'Q7RMeQ7eVaWjJONP+0GUfOStWCKUnlddETS43TLqpzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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