SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86d12c0c5dc529a7699c578612c33f62a3e407678bdf9636da942635f2227272' 
  AND token = '7DRNgrQ+ZDQESbVWtphuFPLddSDxfCsGFw64e6TCHgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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