SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fccc223eaf8db844a67993a550b2013c203b9f3d451137d94d4c1d86542e73b1' 
  AND token = 'DRgKwYMacrhDvG6CTh4IaijUlZBNOILxlXzQQfK4vKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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