SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '483153aba73623a408dc0b1e57ec16578cc5948821dab27fcef65cb3fc8d4c04' 
  AND token = 'uGLTgVFrp9FDRWfgBWMNMmtuh5Gj81kadSzNsq/DvaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}