SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1d0c2759d7fe620991ce93777fe196945f0619d68ff6361a0aa1d2ef0e0cc0a' 
  AND token = 'kAAVUaT2SMkbCTHBZh5mP7SC4Ay+45IBbrcIZokI1dc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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