SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdd5788ea64a4bd8dbbca68620a747208ed83454cba98e647486db5910399a38' 
  AND token = 'g2gkL98E6hZQPdy8ooU28KPEWGRDjKowqxMeu2O0grQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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