SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5266ea2402d3432bd72d1a577d3775943f1095216022e177be6b32ce57423d24' 
  AND token = 'uNgUZPJd8LzT1HTRkdNPB6Puvx04ftooQ4rpn9+Tr4A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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