SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efb7eebf05419e10e1e7a856c8c1a626ac8ce748f054e37a7ca60d12f6a0f263' 
  AND token = 'wDvU8QpkBepBCUlv/iRVPvOOJnBeWegCX8S5NGwq0vY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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