SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7741861c95f4d2e00b3137de3f6bbcb911a017edc126df24e390f602df3c2ed7' 
  AND token = 'biXd5zxrSEzVrETFfx757gmoW5ZM8rknn848dGSNMUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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