SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e1bda69876b74fab45a75b4eec351730d29993953fa90c50241ee9cd8aa8ff3' 
  AND token = 'SfKMWoIVSBT9L8q4DMI0L3Y0wSuJpRfFLB/rfr/eO38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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