SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09f36c42daaf39bd5d3935c2fccbc288c0c91f97b1ff724edb55667da1fe0a64' 
  AND token = 'VD5uuZSQ+gPY+/HkDEeGoBOpMxNeKpwYLdEV+dsfLBY=' 
  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"
    }
  }
}