SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e9971b5cdfa0d69320c2004f978f5046981b49ad3f2b37b3646c3d88ce63cb9' 
  AND token = 'NkaqTYVL/zxFveaSGlJl7z2wP/tK4B3iugn8kPCRHwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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