SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4baaf7eedac40bd1e611b4622f6626023c8a175caae551b4ecf4bd7fbc5d63f' 
  AND token = '1FWch7aSdHr6HlQRleaI155gSWIijRtNABvQpLvDQmA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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