SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bcb699884d00939edc3386cb24256e4432797eaf0a86b8aa04a03bee0a61fa10' 
  AND token = 'ZBvVkQkcDRLgHu1+o2VQuSCYdq+5UcGb5q9OpxzYIGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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