SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b797b824d265552e682cab38a931f4a339fcf1707b171187f7d0623150af0a6' 
  AND token = 'NCuedqzzZJBJfcTuhchOdkVua/SUEKxGIlYXisVbZKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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