SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54bd8e756b6b25a9f4ba2dedfa123e56df9e57638bb52e3f8cee0d353f59f06d' 
  AND token = 'kGLHk7L8G0hBvM2gPj9VlvXWsj4d7d9J+ulsU7kQDzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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