SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85f2f8b40d2cf983cf6f50a34cd31a5e96078cbcd1acaed04ff5e5e0b404464f' 
  AND token = 'U657R6juEKrnxjBXIpGcJB9Izs2Q8EvWQM+TjtglVLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}