SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3ac1ed5cff7b093eaf30a7062f710e7bec03d4821366fa675d9c3e99a19d401a' 
  AND token = 'R+4ZqbWWiB8vZYZ+CN/yOjF/VCg4yPM3VRWvU4VSlmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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