SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b67c1faf9d284d0c15f97888f17307d61362dd9101fd0c5eb103a82fda87b55e' 
  AND token = 'k4pfqBQpGPjE/yv+J186Hxg4OBp+MJPwC7T9hr6ADsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00134

JSON explain

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