SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6937cd61a752034807cf98fac9eb068e00582637f1572b09f2765709b88a76fa' 
  AND token = 'Smk+i0hHpz+fxve2Xmi4ziFDLrjPCJauw5QcpINn0dw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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