SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a5a962ecb2cefa5329bc15a1741cef562926acaeb665a4b7988dfb395c95583' 
  AND token = '8QlH0goGxAwsjyddkC2spkX+41GCgu7RGVaQvhbP8x8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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