SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19075863afc851f080ca90ca256c239292c60c7bb55358127e7d7985cdbb6c61' 
  AND token = 'WiCNDbqXYjCGwBCTLQq44wT97AKN5r3rtp2eqigsiS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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