SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16326f87be7022cddf9a78ca93bc6f35cc43292e2beb6041ba73d0445869f807' 
  AND token = 'vcutzWBw9Pi1tOpmhERc6FnBay9J9+0cOPoCGzFBJnI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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