SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7dfb85831e80e9ff55f1accbc99c32b79f5d812b12b48e6771c668f647f6d43a' 
  AND token = '1v/wJqrj9BJf8kDZpkNOtF32b/9Ig2zskZhJQLG6hAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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