SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cefdd1d3588ddff7f834b1ea4f61f13edc5b1f879f16048d79fcf23ad339be02' 
  AND token = 'bMOTqqDfCIRNpNIgWtte1hEAYQzB3qVw09IT8eaFqUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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