SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0382c81b0ecd2747c04e68f857bdab63929d7dee5e8579afe54adaf207298336' 
  AND token = '6gUevLLafJ+rkYt3yCRTgCDz3c8BV4paXdTBDKoJIE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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