SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '407a8a3141ed1527c7512730b9b3223720f979d73e9be3cdeec2eeacec52f138' 
  AND token = 'OUJesAxJm6pF3k5DPMnesrw6M4gi0sxqcTZqzIjHHnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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