SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '90b22c2070a642215a8f7191330e0803970e2e6d0909a3b0750e41143c196b14' 
  AND token = 'Yzg6KHNXjXmPmbGLf+Ee4mDza5fmIf71PVU20BjezNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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