SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98c04ca81ce52010b02da65f5621526ddb16941f61634247078961017397098e' 
  AND token = 'oqYxeW+Apbw3EmaDYS42rKrOppKu3rCR8Avg2ggXvkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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