SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33d3500faf58bdbbc0412824d111a830c7434ad2a8062c97cf0958d4e75cfa46' 
  AND token = 'BYBdOApYyJDPmX3I5NFLDIzvD2cVPGaVOwael1JfjzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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