SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ba9ba0c718e810e52e6244f3a03936d74a0544f73089d5a91ebfcc5a18fdeed' 
  AND token = 'ItmKz0hpq68NHoAFkaFiBBKIH+Exx2ZGj1fu/J5mGxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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