SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd931033c1b37487704c7b1e1ac06787c9e57454fad605ab19f3c8940a0515d5' 
  AND token = 'Nl20RvKWxv3oEWR6RzAOCs1irLjzdUOIlYmgrgSLBKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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