SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddfa15065f9aa3702fa44765c1b12ef891848aab31f1a34b3eb28172942b870c' 
  AND token = 'Skq1dSu1rK2JYyupNjPiQ1yVw25DNHbrUJXl3KBe0Qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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