SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23df024ca56eb46861f68d4ef988f45f5ac961b9addc6e7734417a07bd72d9bf' 
  AND token = 'R9XMxBtWW2l61Dnfb04mHLGke6w6yHH2siXukuj6FvA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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