SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '887d3ba46608566711dc9b773aebb689e8661d79bd09390a14bb9f994b5ce0d6' 
  AND token = 'fztOsIsAQ1Tpq2CdA5UKK/Z8bF51idJckyIjPVnpMos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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