SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '662ddc2d21f4881cd47725290c27f6cea99408855ddefd5067f3f0d64f61ce7c' 
  AND token = 'na97waT4TDGlmm4TIC+CWuUQV2RgfmwPspsnLhtbFt8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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