SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e4fb35a9c168c2370b98f2d79ce19bb23f6b6a4442c4d931f466d64315ef82a' 
  AND token = 'nZ3Nt86CUwBkrH3MTj+khQJKIdbCveFJACd1IYTSJKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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