SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaa7cf3c2a3a3ffc8ba6b15b201f20d5de270ceef0309f5d2dbd875984fcdbf0' 
  AND token = 'HKhfXXrFeFPIfhMPntzPMiJmqZMARgNAbXIqIdPPsPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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