SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84e4b10c3c74e6e48ab69bd4a0946d6316fea51c028d6aeafb7dd69db1794b1e' 
  AND token = 'ygSBSF5M9ypBFukfnOUSpFw+NeCFwGMpJ1R9OFyI3xo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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