SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ef13b58ae493f669c55714ff923100f85fcb5e4559c7ec2d4041d4f0e79f18f3' 
  AND token = 'B1JWwY+j/8pB8G3SWD6K89WY5ZWu+F3kNhERxoj9tQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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