SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfdae39d8017e7510711963655b2b802b60c27da863afb7aa89b670c563d2eb2' 
  AND token = '0/aIcdczyF6+0f2PnrIy6jUY/hZcebolbkFHPZHTENY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}