SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f7050e54562374aa305d33455d3f60817911587e34b202fb93aac9427ccd9853' 
  AND token = 'u/4DhxDBxXUyU7ZdaYYz3j+v8ePMUJ+BNZ61X1wXIGc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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