SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '23e26482a879fbc1faa1f49e74e59846d01c99d20aa85604086b8b63230bbdc3' 
  AND token = 'YDQ3YnS3Kuz1tWRD1Ir3gyHPjtJWK9Yt023KGulQv5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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