SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df4dd3d811f34ec31755278ea91191e8e4d010b4a5cb43a1d2a5257b8952dc9b' 
  AND token = 'O0r4Vj84Cj7KYkhtoXvu4L36XvTVn9LsKCzWIsuWZUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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