SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea5046ccead8b252b38ac8071c651e6793ad356cc4042fdde52d963f035cfeb3' 
  AND token = 'rCNoHdUFT33bmuQsMH22NALwLHqaqeaJtIroKy4AEqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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