SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e39d3c487b5a738b83200488ee4ae937b56999879c8677e01998bc0ccf698308' 
  AND token = 'MIYUArjDvoEfhggtooAkCDcZxnG2TEXHTU3By9NpCiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}