SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd42f1ca425d5598ddfe8b63c2bfac47083ff4aa80f12d1e8c43eb4487412219c' 
  AND token = '4TOcdDdJbqcjw8KQqzbwrbqfMlGDrfkEgPSm2w0ibws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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