SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a597ad5286d403918b531c66c399f32565853d9242140e5d758258cd95fce5d' 
  AND token = '/7v3Z7RFMHhGyBqzWRM5MN5pX3gBeZlpyZUFzC/mRzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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