SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dfac15b80be68f07298fffbd6ec299f292f2e0b4618412d09059cec0cef58dbc' 
  AND token = 'geFfPv7wbGxRIHKkyPnnlMPSopsvhnFBRbssvOJiFPs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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