SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6cefa92292314b65af50c05e1ae2835e15bbc6778c81d42b0714af57669c9b0' 
  AND token = 'H0UKrSqJrni3NIq31/tlS6nxYsVCtRib2/4Vi9bnmDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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