SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '68b290d91b8ef84c1a79cb7675552fc4d11a5141166e0a9e39bc6e7a841f002f' 
  AND token = 'P2H5ot7tix1i3H6EezBe0VBOb8wGdlh+YjuzJZXUPBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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