SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dd9f3b7d01fe64517baf59a5318c196b2d63751559ce0f5128131eb98068c23b' 
  AND token = '98KPJWwBBajI/6zaLl5hI/YcHWBmMxQANlsIbAAxvM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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