SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '38da3a07a841db387881821f39ea9b3e735ae6e9fa9d0428bcf4bba952c6c8a9' 
  AND token = '71b3RjitjNWkMRngFDJbdwDZSQ7xBezMm/Yi/FSUSMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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