SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c323fed931b01dbd83eacfe2e3ede7c88edf12122d160b845c58139f16e9fe44' 
  AND token = '6puHOwyYHeZYmFh20msXzTDb6rH38CfHUV/XQ7KJ5vk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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