SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '898a21f118112700ba71624a5844b3cf3f15a2284607b77326da8abf4f2eef92' 
  AND token = 'rykHyVaP31BJd/Bp1Tpf7ipx0vBnrJvMVu1cMG8NW4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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