SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b29f6aeccc35cb48ebd053f0755b73968b673eb3709b00703490295f5bfbecbb' 
  AND token = 'nFrChAeOXvlm6frO6Ia/kLOcbQwQtqO9GXZJABqtWi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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