SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92016a8e3376529c16c551704ac3f17da7114422b4ae0c5f3a4aa03de93d0c13' 
  AND token = 'f5gwMeFvnMYTirI4D5Sh8q62EE0Yn7cRox6yb+AnQ6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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