SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9670fcb7f102effa29cfcbaf3965d31bf5fb594ae0e7671adb9be252df1e5c9' 
  AND token = 'IxNqwOsKQS+l6uvjfEN87fZUYDCrzpsXqX/U4MxwFKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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