SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd36a459e95b80aed81e9995f0451755c95fb7663baa500978002856f314f021b' 
  AND token = 'VVZyF/g2U468myP3nbtJnLM96F4BQsh41fbvcF5odWQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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