SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '990a05bc4a05a7fc42c8297e9ffe974972417fdac0473405e59abe9848d3e031' 
  AND token = 'AuxCUQH6K7a76+5SLVHXsjarxPVLU38BgHqxSurhyhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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