SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e422cab7804394d6b5b6b30d3bd0cba4f826b9766b38276e6f08767d709425d1' 
  AND token = 'drZ82vg9EPxIAFzZwfIvIRVDa94VWtljJdIkuMInyIE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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