SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69d5732cfdd95a6f3fcf3589208f7a578b9a64436a0495f5c4bb5a9c9ee09f43' 
  AND token = 'SpgcrD2SvbGkQd5dEc7duC/aIt1VJPOzh7R/bIxap6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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