SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1b80855ca3b875d36270c9e6f9b49deb02c046906c0f14ae76429186f5825fa' 
  AND token = '8ZwgPsaUvirMSpM2qClheRrQbAm5dywwzVRoBrYkEhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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