SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4e70dc05e343c8770a173dc01b93fed96b6de9a64b788349cccdfd3701d829ec' 
  AND token = 'yzxpmM0ItuS5f1t00B7Nz+CcBddI21P6rfzhhKUQTos=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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