SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd89b6d3c03c286e9e022d554b3958797095dbb5b1819f20bc1758c49cbb74c74' 
  AND token = 'gcFdCJLuwPoDqI8z5jCmYD3Srl7+4mah+XxwXeIEKhY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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